This invention relates to an additional-service communication system in which an additional service for which a request has been issued by a subscriber apparatus is provided to the subscriber apparatus from a provider apparatus via a transmission line, as well as to a method of charging for this additional service. More particularly, the invention relates to a charging method and additional-service communication system in an ATM (asynchronous transfer mode) network for providing an additional service by ATM cells, wherein the additional service is charged separately from the charge for communication utilizing the ATM network.
The provision of additional services such as VOD (video on demand) and digital broadcasting utilizing ATM networks is growing more widespread. With a view to providing such additional services using ATM networks, there is a need to charge for the additional services per se. Hence there is demand for an appropriate charging method.
In general, charging for an additional service in an ATM network that provides an additional service by ATM cells involves paying the provider a fixed amount on a monthly basis irrespective of the amount of information supplied by the additional service (i.e., irrespective of the cell flow rate and supply time). However, it is now demanded that a charge commensurate with the amount of information supplied is collected from the subscriber. In order to accomplish this, it is required that the provider calculate the charge by metering, on a per-subscriber basis, a charge conforming to the amount of information supplied. FIG. 63 illustrates the configuration of a provider apparatus having such a charge calculating function.
Specifically, FIG. 63 shows a provider apparatus 1 for providing an additional service by ATM cells. The additional service is received by a subscriber apparatus 2 via a transmission line 3. A transmission apparatus 4 is provided between the provider apparatus 1 and the subscriber apparatus 2 and is equipped with an ATM switch and the like. The provider apparatus 1 includes a service controller 1a for communicating with the transmission apparatus 4 and subscriber apparatus 2 and controlling the provision of an additional service, an ATM controller 1b for converting various signals (video, audio, data) to ATM cells and converting ATM cells to various signals, a basic transmission line controller 1c for converting ATM cells to transmission signals and transmitting the signals over the transmission line 3, and converting transmission signals to ATM cells, and a storage device 1d for registering various information regarding the provider apparatus. The storage device 1d has a service table 1e in which various information for additional services is registered, and a charging table 1f that stores various information for charging purposes. The provider apparatus 1 further includes a charge metering unit 1g which, based on the charging information in the charging table 1f, meters and stores, on a per-subscriber basis, a charge in accordance with amount of additional-service cells (e.g., video cells).
If the subscriber apparatus 2 transmits a request for provision of an additional service to the provider apparatus 1 via the transmission apparatus 4, the service controller 1a of the provider apparatus 1 refers to the service table 1e in the storage device 1d, transmits routing information to the transmission apparatus 4 accommodating the subscriber apparatus 2 and establishes a path between the provider apparatus 1 and subscriber apparatus 2. The service controller 1a then starts sending the transmission apparatus 4 video cells that have been designated by the subscriber apparatus 2. Based upon the charging information in the charging table 1f, the charge metering unit 1g of the provider apparatus 1 meters, on a per-subscriber basis, a charge in accordance with the amount of usage of the video signals and stores this charge in memory.
Thus, when it is attempted to implement a method of charging for additional service in accordance with the amount of information supplied, the provider apparatus 1 is required to have a function through which the charge for each subscriber is metered. Consequently, if the number of subscribers is large, metering the individual charges constitutes a heavy burden. This influences the primary function of providing the additional service per se and it is likely to result in poorer service.
Further, in case of an additional service in which multicasting is performed in the transmission apparatus 4 for digital broadcasts or the like and channel changeover control is carried out by the transmission apparatus 4, charge based upon amount of cell in regard to each subscriber apparatus cannot be metered in the provider apparatus. Consequently, the only feasible method of charging available is to collect a flat rate on, say, a monthly basis.